1. Field of the Invention
The present invention relates to a surface-type fastener such as a hook-and-loop fastener including a pair of interengaging fabric fastener strips, one fastener strip having on its one surface a number of hook-shaped or mushroom-shaped engaging elements engageable with a number of loop-shaped engaging elements projecting from one surface of the other fastener strip.
2. Prior Art
A common problem with known surface-type fasteners was that engaging elements in the form of hook or loops would tend to come off the individual fabric fastener strip or to become objectionably loose as the two fabric fastener strips were interengaged and disengaged repeatedly.
To this end, it is known to apply synthetic resin over the element-free rear surface of the individual fastener strip in order to fix or stablize the engaging elements so that they retain their shape and position, thus preventing the engaging elements from being removed or otherwise impaired. However, this backing with synthetic resin would make the fastener strips less flexible so that a sewing needle is not allowed to smoothly pierce the individual fastener strip when the latter is sewn to a garment, for example. U.S. Pat. No. 3,009,235 is believed to exemplify the prior art.
Japanese Utility Model Post-Examination Publication (Kokoku) No. 57-15684 discloses a hooked fastener strip having a plurality of rows of uniformly spaced openings for the passage of a sewing needle. This prior fastener can be sewn at only a fixed pitch of stitching which pitch corresponds to the inter-opening distance.
Another attempt has been proposed by Japanese Utility Model Post-Examination Publication (Kokoku) No. 57-27289 in which the individual fastener strip is made of a woven or knit fabric having non-woven or non-knitted areas in an effort to facilitate the penetrating of a sewing needle. However, because of this non-uniform fabric structure, uniformly shaped engaging elements are difficult to achieve. Further, the engaging elements at the non-woven or non-knitted areas are weak-kneed, thus causing non-stable interengagement of the opposed fastener strips.